Man-of-the-match and 20-point hero Tadhg Bennett landed a last-minute penalty to earn Shannon a draw in the latest installment of the local derbies between these two great Limerick rivals.
Garryowen led at Dooradoyle after eight minutes when referee Michael Black reversed his original decision to award a penalty to Shannon. Inside centre Declan Cusack, from 45 metres out and six in from touch, managed to split the posts.
Shannon suffered another blow just four minutes later when their scrum half Rob Guerin had to retire injured and he was replaced by Alan Bennie.
To compound the visitors' problems, Tadhg Bennett missed a penalty chance and Garryowen got in for a try after 23 minutes from right winger Adam O'Loughlin.
Flanker Paul Neville sent a well-weighted kick through and O'Loughlin won the race to the bouncing ball in the corner with Cusack unable to add the extras.
Straight from the restart Shannon were awarded a penalty but Bennett's effort drifted to the left and wide of the posts.
Shannon's sense of frustration increased when their influential number 8 David Quinlan was sin-binned for a professional foul as Garryowen almost got in for another try. From the subsequent penalty, Cusack made it 11-0.
Finally Shannon got a lucky break four minutes before the interval. Bennett charged down an attempted clearance from Cusack and gathered the ball to touch down for a try that he was unable to convert.
A fourth penalty by Cusack made it 17-5 but within a few minutes of the restart Bennett finally found his range to give Shannon hope of a comeback.
Bennett landed another penalty after 51 minutes to further narrow the gap when the Light Blues were penalised for a scrum infringement. Player-coach Stephen Keogh was to the fore as the Shannon pack showed great grit and determination.
Their talented out-half struck again when this time Garryowen flanker Kieran O'Gorman was yellow carded, and Bennett stepped up to make it 17-14.
Bennett tied it up after 64 minutes when Garryowen were penalised for being off their feet. It looked over for Shannon when Cusack landed his fifth penalty after 75 minutes, with the Munster-capped player almost putting his centre partner Corey Hircock over for the clinching try just moments earlier.
But just at the finish, the increasingly influential Bennett earned a share of the spoils for Shannon with his fifth successful kick at goal – a tremendous effort from 45 metres out.
Referee: Michael Black (IRFU)